Social Bookmarking

Definition

Social bookmarking is a method for Internet users to store, organize, search, and manage bookmarks of web pages on the Internet with the help of metadata. http://en.wikipedia.org/wiki/Social_bookmarking

http://www.youtube.com/watch?v=x66IV7GOcNU

Features

organizing
sharing sites
networking
quick reference

Examples

Education
edu-tagger - http://edutagger.com/ K-12 social bookmarking network

Math Education
Once you are in one of the social bookmarking websites you can search for specific math related websites.

General Interest
They are free but you need to join in order to access the information.
Delicious - http://del.icio.us or http://delicious.com/
Furl - http://www.furl.net/